David L. Katz, MD
Photo: Mackenzie Stroh
Q: I do an intense Bikram yoga workout twice a week, and I struggle with what foods to eat, and when, before I work out. My goal is to have lots of energy during the workout but not to feel as if I'm still digesting during class.
— Madeline Jhawar, Chicago

A: Last summer at the Beijing Olympics, Michael Phelps won an incredible eight gold medals on a diet of chocolate chip pancakes, ham and cheese smothered in mayo, and sugary drinks. He could get away with this because the physical demands of his training and competition required 12,000 calories a day, four to six times what an average man might need. But mere mortals like us have to use a little more caution: Food not only fuels the body in the short term but also contributes to health over the long term, which is why I don't advise the Michael Phelps approach.

Typically, sessions of challenging and intense Bikram yoga last 90 minutes, usually burning 800 to 1,000 calories. To sustain your energy, I recommend whole grains and lean protein such as eggs and nuts. The grains will provide carbohydrates that your body can readily convert to energy. And the protein can be put to use repairing and building new muscle following your workout, while the high-calorie but healthy fats in the nuts will fill you up quickly with less bulk. But you'll have to experiment to find out what works best for you. Some options include a small bowl of whole grain cereal with skim milk an hour before your workout; a hard-boiled egg; a cup of nonfat yogurt with some nuts and fruit mixed in. Another way to get maximal nutrition with a minimal sense of fullness is by making a fruit and yogurt smoothie.

Because I prefer to work out in the morning, I do it on an empty stomach and fuel up afterward with a breakfast of mixed berries and whole grain cereal. How well your body performs during an a.m. workout depends in part on a balanced diet the day prior, which provides the liver and muscles with the glucose they need to make glycogen, the primary energy store you'll burn in your yoga sessions. Try out my suggestions above—you should be able to find something that works for you.